重组为 backend/clients/docs 三层结构，并清理 git 污染。

将后端迁入 backend/，完善根目录 .gitignore，删除误提交的 .mypy_cache 缓存文件。

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/tests/test_voice_confirm.py

@@ -0,0 +1,67 @@
+from app.services.voice_confirm import (
+    build_prompt_text,
+    match_voice_choice_against_candidates,
+    parse_voice_choice,
+)
+
+
+def test_parse_voice_choice_substring() -> None:
+    assert parse_voice_choice("用的是纱布对吧", ["纱布", "缝线"]) == "纱布"
+
+
+def test_parse_voice_choice_numeric() -> None:
+    assert parse_voice_choice("第2个", ["纱布", "缝线", "钳子"]) == "缝线"
+
+
+def test_parse_voice_choice_ordinal_chinese() -> None:
+    opts = ["纱布", "缝线", "钳子"]
+    assert parse_voice_choice("第一个", opts) == "纱布"
+    assert parse_voice_choice("第一个。", opts) == "纱布"
+    assert parse_voice_choice("第2个", opts) == "缝线"
+    assert parse_voice_choice("第二", opts) == "缝线"
+    assert parse_voice_choice("选3", opts) == "钳子"
+    assert parse_voice_choice("选项2", ["纱布", "缝线"]) == "缝线"
+
+
+def test_parse_voice_choice_single_chinese_digit_with_few_options() -> None:
+    assert parse_voice_choice("一", ["纱布", "缝线"]) == "纱布"
+    assert parse_voice_choice("两", ["纱布", "缝线"]) == "缝线"
+
+
+def test_parse_voice_choice_negative() -> None:
+    assert parse_voice_choice("不是", ["纱布", "缝线"]) is None
+
+
+def test_build_prompt_contains_options() -> None:
+    text = build_prompt_text([("纱布", 0.4), ("缝线", 0.3)])
+    assert text.startswith("请确认。")
+    assert "第1个，纱布。" in text
+    assert "第2个，缝线。" in text
+
+
+def test_build_prompt_empty_options() -> None:
+    assert build_prompt_text([]) == "请确认。"
+
+
+def test_parse_voice_choice_empty_options() -> None:
+    assert parse_voice_choice("第1个", []) is None
+
+
+def test_match_voice_against_full_candidate_list() -> None:
+    assert (
+        match_voice_choice_against_candidates(
+            "刚才用的是止血钳",
+            ["纱布", "缝线", "止血钳"],
+        )
+        == "止血钳"
+    )
+
+
+def test_match_voice_longest_candidate_first() -> None:
+    assert (
+        match_voice_choice_against_candidates(
+            "拿的一次性止血钳",
+            ["止血钳", "一次性止血钳"],
+        )
+        == "一次性止血钳"
+    )